The present invention relates to a semiconductor device and a manufacturing method thereof, and is preferably applicable to a semiconductor device including, for example, a solid-state image sensing element, and a manufacturing method thereof.
As a solid-state image sensing element (which may also be referred to simply as an image sensing element) for use in a digital camera, or the like, a CMOS image sensor using a CMOS (Complementary Metal Oxide Semiconductor) has been under development. The CMOS image sensor includes a plurality of pixels arranged in a matrix, and each for detecting a light. Further, in the inside of each of the plurality of pixels, a photoelectric conversion element such as a photodiode for detecting a light, and generating electric charges is formed. The photodiode is a pn junction diode, and is formed of, for example, a plurality of n type or p type impurity regions, namely, semiconductor regions.
Japanese Unexamined Patent Application Publication No. 2016-111082 (Patent Document 1) discloses a structure in which a plurality of p type semiconductor regions and n type semiconductor regions are arranged alternately in a comb teeth shape in order to increase the capacitance (number of saturated electrons) of the photodiode.